Ryan Giggs claimed Daniel James was 'acting' after the Manchester United winger hit the deck after taking a knock to the head during Wales' draw with Croatia.
James went down in the and had to be treated for several minutes by the Welsh medical team.
It initially appeared as though James had been knocked out but he was allowed to play on after treatment.
Former Hull City midfielder Ryan Mason, who was forced into early retirement after fracturing his skull while playing against Chelsea, was one of a number of people who voiced their concern about the decision to allow the 21-year-old to play on.
But Giggs suggested after the game that the United man had just made the most of the situation.
"Dan James went down and stayed down with a bit of acting really, but the medical staff went over and he was compos mentis," the Wales manager told Sky Sports.
"Then at half-time we did all the (concussion) tests and he was fine."
Giggs also elaborated on his comments in his post-match press-conference: "He stayed down, there was no problem and then at half time he passed all the tests. He told the doctors, 'I'm not moving, I'm just sitting still'.
"Not to get anyone sent off, he was just using his nous."
James gave an update after the game where he confirmed he hadn't been knocked out: "I'm fine. I think he just caught me in the head but I didn't get knocked out fortunately."
